Piston ring spacer-expander with overlap indication means



Jan. 19, 1965 F. e. WARRICK 3,155,331

PISTON RING SPACER-EXPANDER WITH OVERLAP INDICATION MEANS Filed June 25,1962 2 Sheets-Sheet 1 4, jg 4121M all L122 ATTOR/VE'YS 1965 F. s.WARRICK 3,166,331

PISTON RING SPACER-EXPANDER WITH OVERLAP INDICATION MEANS Filed June 25,1962 2 Sheets-Sheet 2 ATTOR/Vf/S portion that is greater than the boredian iet spacen expander whose ends are self-aligningdur $166331FHSTGNRWG SPACER-EXPANBER W H UVEAPIHHHCATEON MEANS Frank rGe Warriclr,Mrisiregon, Mich, assignor toSealed Power Corporation, Mnskegon, Mich, acorporation of l iiehigan i Filed June 25,1sa2', sail N z'osnso 1 p21Claims. o1. 277-'-1s9 This invention relates to a spacer-expanderotapiston oil ring for an internal eombustion' engine and inparticularto an oil ring of the type having aicorrugated; partedspacer-expander which must have its ends aligned to func tion properly.

7 In many prior art oil rings a circumferentially compre'sgsible'spacer-expander is located between upper and lower rails forurging the rails radially outwardly intofoontact with the bore of thecylinder. Such rings 'function'prop- 3,166,331 Patented l an, l9,

v tion'fof the piston .nd oil ring assembly into a cylinder bore.

7;; Another object is to provide a spacer-engender that 'indL cates'when the ends o f the spacer-expander are overlapped by: preventinginsertion of the piston and oil ring assembly into a cylinderbore. i

Still further objects. are to improve "known spacerexpanders by a simplestructural change in the end portions, requiring only minimum productionchanges and, additionally, to provide, by only slightmodification, ,a

' spacer-expander having self-locking ends.

In the drawings FIG. 1j is a top view ofja spat??- expander madeinaccordance with the present invention,

erly only if the ends of the spacer-expander are abuttingwhen the pistonand oil ringassembly is inserted within the cylinder.Suchfspacer-eXpanders are self-supporting H in that when thespacen-expander ends are' ab u'tting and the spacer-expander iscompressed circumferentially, it will operate effectively withoutengaging the bottom of an oil ring groove in the piston. Qne'typeof'spacerv expander is in thefiorm of a parted'ring formed. withradially extending corrugations "as disclosed in U.S. Letters Patent No.{2,789,872, issued-to M. Olsen [on April 23, 1957. However, either pn'orto or during'inser- @91 Q t e pi ton wi in t ,eyl nd i e s of thepacer-expan may become oyerlapne g inadv rt t y 'With a porrgnatedspacer-expander of the' type disclosed I including a fragmentary showingof a rail used therewith. FIG. 2 is an enlarged perspective showingabutting fend portim s eithe spacerexpander. i

FIG, 3 is a fragmentary view showing end'portions of I ribbon stool; forthe spacer-expander of FIG. ll: 1 FIGS. 4, 5 and 6 illustrate variousorientationsof the ,s pacer-e rp anderends which can occur duringinsertion of i h and oil ring assembly within a cylinder bore. F1

. locking ,of'the ends.

insaid j'OlsonQ patent, if the ends oflthe spacer-expander becomeoverlapped theoverlapping corrugations canriest within one another. In rse the oil ring of the aforebottorn' ofthe joil ring 'groove, Thisspacing is suificientto accommodate the overlapped endsoftheispacer-eirpander and permit the. insertion lot a piston and onring assembly.

within the cylinder bore even thoughthelspaceneirpander ends areoverlapped; Whenjoverlapping ,is present'flltlie spacer-expander willnot urgerthejoil iing outward against the cylinder bore inthevniannefinter fdedjl Improper cooperation t between the cylinderbore. and the] oil ring assembly may result'iiiexcessi've oilconsumption,- sr'noking and loss of power.

mentioned patent is spa ecl radially outwardly from the);

FIG. 18 is a fragmentary view showingfend portions of I ribhori stockfor theQspacer-xpander; of FIG. 7,-

i, Eli; 9 iisaa ienlarg d vi m and pottiqgs of i s s n nder "or F1 17lin locked interengagernentg" y FIG, we a view are aloing lines'10-.il02otEI G, 21

3 sgshowing' thepistori and oil-ringassemblypesitioned withinaf'cylinderbore. i i i For purposes of illustration the p'arted-spacer-expander is 'lla idaily otthe type disclosedin the previouslymen- .tljonqgl patent tolOlson, except that ,theend portions "have beenmodified inacc ordance with-the present invention, Oil

fle 11 lcli eed nan ra l 2 Spa e neirpanderfn comprises a'parted ring"14 having a'c on- ,secutive series (it alternating'inward and outwardcorru- The presentinvention solves the problems created-by overlappedspacer-expandererids in prior artiby'proyid- .ingeach'ofjthe ends W'ithareturn bent portionthat forms anfljacute included angle with thecontiguous portionl of the spawn-e pander. Byisuch an arrangement,overla ,ping of the, ends is minimized-but if it .does eec r the pistonand 'oil fring" assembly cannot bdinserted wlthin thecylinder bore. Whentheends ,of thespacerexpa'nder of the present invention are slightlyrnisalignedor partially overlapped, the return bent portipnswillfusuallycam the rnore fully explained in the aforementioned patient, after endsinto alignment when the oillr'inglis compressed-prior cylinder. If'for'some reason the eamming action does substantially, when the ringis'compressed for insertion inthe cylinder'bore one of,-the returnbentlportions is The;

crushedor bent against the ,contiguousfportion. combined radialthicknesses of the {crushed return bent portion and the'contiguou'sportion are suchthat lthelpisto ri and oil ring assembly has a diarneterat Lille overlapging a he e ed within the piston andoil ring assemblycannot be iris" bore. f Therefore,

laniobject r this mveritibnii to proyide a to inserting the piston andoil ring assembly withinlthe not occur, as for example, where theends'are overlapped '5 gations, the corrugationsfbeing formed byinner'erowns 16 land outer'fcrowns' 18, connected .by upper and lowerlegs 17 which are .separatedt-by slots IQ Spacer-enpander 1,2 Lrnayfbeformed from a stripof iiat metal ribbenlstoclc as shown in FIG. 3. 1Inner lips 20 extend vfrom-th e, 1pper and lower edgeso f in'ner crowns16. Similarly outer lips illrfr r ie i arm: t e uppe arid-lower ges ouer-c own ,18 but to a lesser .extent than the inner lips 20. The modi-'fied end'por tion'szofthe instant invention-are indicated generally "at22; l

i ring 11 includes two parted ;rails '24 t h 'e' b lap rt d fhi h e n ap th rejre w e f (FI hr min EI ow- 311 24, a e Q carried on opposite,upper and loyver, edgesof-the spacer- .zxr ade i l a d ta on the t rilips 1 The inn edges 23 of thera ls '25 are engaged by inner lips 20.As

the oil ring 111135 been circumferen-tially, compressed, and the pistonand oil rlingassernblyinsertedwithincylinder bore 26, lips' ZOof thespacer-expander urge the rails 24 radiallyfontward to maintain theouter-ledges 35 of rai1 s24"in contact bore With 'oil ringflllretainedin oil ring gror'ive 40 of piston'39 inthis manner. and,assuming-the oil: ring is centered in the oil ring "groove, thereis'aradial clearance orlspacirig 44 between the bottom 42 of groove 40 andmean 'ring 11. The usual clearanceiexists :betwe'entheoiiter stir'face43 of piston 9 As best illustrated in 38,-respectively; ;Preferably"theacute included angle g n I V T7 is a 'perspective shhwinga modificationof, the i "spacer-expander of to provide properly aligned FIG. 2, theends of the 'spacer- ,egrpander'ilz comprise elbows 28, 3t) formed-byreturn pentportionsfil'iafiandthe-contiguous,innertcfowns 36,

between each return bent f brokenflines at 45 in FIG. 6. spacing 44 andparticularly the maximumjspacing 45 "was sufiicient to accommodateoverlapped and nested, I spacer-expander ends. and permitted the pistonand oil "ring assembly to be insertedwithin the bore. instant invention,however, if'the ends are overlapped as shown in F IG. 15 return bentportion 32 lies between *the inner crowns 36, 38; Therefore, when therails are compressed return bent portion 32- will be crushed to lie ofcrown 36 exceed the maximum available spacing 45, so that the diameterof the piston and oil ring assembly the inner edges 23 of the rails 24and the oil ring groove 40; whereas in priorart devices when crowns '36,38. fit within the maximum spacing between the rails and the bottom ofthe the oil ring is not centered, but threethicknesses will not.

As shown in FIGS. 7-9,"the spacer-expander ends may portion 32, 34 andthe contiguous inner crown 36, 38 is within the range of from 35 to 40degrees.

In installation the oil ring lllbis first slipped over piston 39 intothe oil ringgr'o'ove 40. Then to'insert the piston and ,oil ringassembly withinthe cylinder bore 26, the

rails'24 are circumferentially" compressed orcontracted to close gap 25(FIG.. 1) and thus reduce the diameter of the oil ring to a dimensionequal to or slightly less thanuthe bore of the cylinder. Compression ofthe rails places the spacer-expander 12 in circumferential compression.If at the beginning of this compression step broken lines in FIG. 4,elbow 30' will be cammed radially inward down the inclined end portion32 intothe properly aligned position shown in full lines, FIGS. 4 and.show the piston and oil ring assembly inserted within the bore 26 withthe oil ring 11 compressed. In FIG. 4

the oil ring is shown centered with respect to the groove 40 on thepiston which results in the-spacing 44 previously referred to. In FIG. 6the piston is shown shifted v to the'leftin the cylinder bore a maximumextent so fthatthe radialdimension-between the bottom of groove 40andthe bore of the cylinder is the maximum value adjacent the" overlappedends of the spacer-expander; In this position of the pistonthe maximumspacing that would be present between thebottomof groove40 and the endsof the spacer-expander are not properly aligned "as illustrated by theoverlapping elbow 30' shown. in

provided with-a return bent portion, each return bent portion forming anacute included angle with the contiguous portion of said parted ring. g

2.A spaceraexpander as set forth' in claim 1 wherein each of saidreturnbent portions extends radially outward from said contiguous portion.

degrees.

a properly arranged spacer-expander is indicated by i In prior artdevices the With the flat against inner'crown 36 in the most extremesituation as shown in FIG. 6 The combined radial: thicknesses the returnbent-portion 32 and 'its contiguous inner at the point of overlap isgreater than the bore diameter. The rails cannot be contractedsufiiciently to permit in- :sertion of the piston and oil ring assemblywithinfthe bore.

In other words, when the ends'are overlapped there are three thicknessesof ribbon stock, i.e., two inner crowns 36, 38 and one return bentportion 32, between the bottom42 of nesting occurred there were onlytwothicknesses of ribbon stock, i.e., two inner crowns corresponding toinner Two thicknesses of ribbon stock will groove when includea lockingarrangement comprising notches 46, 48 cut in the elbows 28,30,-respectively, and extending into. the inner crowns 36, 38 and intothe return bent portions 32, 34. The unnotched portions of theelbows 28,form projections 50,52, respectively, adaptedto register and interfitwith complementary notches. More particularly, the projection 5:0, forexample, registers with .notch- 48 of elbow 30 and is held againstradial displacement by edges 54, 56 when thespac er-expander iscircumferentially compressed;

While theinvention is particularly, adapted to prevent nesting ofoverlapped inner corrugationsin. thecorrugated spacer-expanderparticularly disclosed, it should be underother types ofs'pacer-expande'rs 'to minimize" overlap, as

:wellzasx indicate when overlapping occurs.

3. 'A- spacer-expandefias set 'forth in claim 1 wherein each includedangle is within the range of from to 4. A spacer-expander as setforth inclaim 1 wherein said ends include means for locking said ends in radialaalig'nment. p p j 5. .A', spacer-expander as set forth in claim 1wherein peach return bent portion and the contiguous portion form anelbow, said elbows being formed with notches and projections adapted tointerfit with one another to lock 'said ends, in radial alignment. I I

6.-*A spacer-expander as set'fo'rth in claim 1 wherein said ringcomprises a continuous corrugated strip of resilient materiaL' w 7."Aspacer-expander for supporting, spacing, and

j diltwardly urging generally fiat, parted rails in a piston oil ringassembly, said spacer-expander comprising a parted ring of theself-supporting type, said parted ring having ends that abut when saidspacer-expander and said rails are disposed in anfoil ring grooveandsaidspacerexpander is in its operative circumferentially-compressedcondition, said parted ring being formed from a continuous strip ofcorrugated material, said corrugations comprising alternating radiallyinner and'outer crowns interconnected'by legs, the corrugation at eachend of said spacer-expander having aterminal leg anda contiguous innercrown, and each of saidterininal legs being return bent at, an acuteangle to'its contiguous inner crown. 8. A spacer-expander as set forthin claim 7 wherein each return bent portion and thefcontiguous innercrown form an elbow, said elbows being formed with notches andprojections adapted to interfit with one another to lock said ends inradial alignment.

9. In a piston and oil ring assembly adapted for insertionwithin thebore of a piston cylinder, an oil ring groove in said piston retainingsaid oil ring, said oil ring comprising fiat parted, circular rails anda spacer-expander for supporting and spacing said rails and for urgingsaid grails outwardly against the bore of said cylinder, saidspacer-expander comprising a parted ringfof the selfsupporting type,said partedring having ends that abut when said' spacer-expander andsaid rails are disposed I stoodthat the return bent end portions can-beused on in an oil ring groove and s'aidspacer-exp'ander is in itsoperative circumferentially-compressed condition, each of said endsbeingprovided with a return bent portion, a

each return bent portionforming an acute included angle with thecontiguous portion of said parted ring, the radially innermost edgeportion of said oil ring having a predetermined maximum spacing from thebottom ofsaid oil ring groove when said piston and oil ring assembly is"inserted within said bore, thecombined thicknesses of a return bentportion and a contiguous portion being greater thansaid predeterminedmaximum spacing whereby if saidends of said spacer-expander areinadvertently overlapped, thecombined thicknessesjof a return bentportion and a contiguous portion prevents contraction of saidrailsradially sufliciently to permit insertion] of the piston and oilring assembly within said cylinder bore. H 10. Ina-piston and oil ringassemblyadapted for insertion within the bore of a piston cylinder, anoil ring "groovehin sai di piston retaining said oil ring, said oilurging saidrails outwardly against the bore .ot said, cylin-.

ring comprisingflat, parted, circular 'rails rand aspacer expander forsupporting and :spacing' said rails and for der, said spacer-expandercomprising a parted ring of the g self-supporting type, said parted ringhaving ends that abut when said spacer 'expander and saidrails'aredisposed in an oil ring groove and said spacer-expander is in itsoperative circumferentialiy-compressed condition,

each of said ends being provided with @Tfiilllfli bent ,pr.

tion, each return bent .porton forming'anfiacute included angle withthe; contiguous portion of said parted ring, the bottom of said oilgroove "haying-a predetermined maximum spacing from said here when saidpiston and oil ,ring assembly, is inserted within said bore, and saidpredetermined maximum spacing beingiinsjufiicient' to accommodatesaidoil ring when sfaid'.spacer-expanderflends are'overlapped. i j ,v

' 11. Inf a piston and oil ring assembly adapted for insersaid'nailsradially-suificient ly to permit insertion of the; piston and oilringassembly within said cylinderbore f L16. In combination a p stonr n oilIi g as mbly; and: an engineljcylinder, said piston having an oil ringgroove,

saidoil ring assembly being retained in said groove,said' piston withsaid oil ring assembly being inserted within said cylinder, said oilring assembly comprising flat circular parted rails -suppo,rlted by aspacer-expander urging said rails outwardly against the wall of saidcylinder, said spacer-expander comprising a parted ring having each ofits ends provided with a return bent portion, each re-,

turn. bent portion forming an acute included angle with;

- the contiguous portion of said partedgring, the radially innermostedge portion of saidioil ring having a predeter tion within the bore ofa piston cylinder, an oil ring V groove in said piston retainingsaid'oil ring, said oilring comprising flat, parted, circular rails and,a spacer-ex pander for supportingand spacing said rails and for urgingsaid rails outwardly against the bored said icylin den saidspacer-expander comprising a parted ring of the selfsupporting type,said parted ring having ends that abut when said spacer-expander andsaid rails are disposed in an oil ring groove and said spacer-expanderis in itsv operative circumfere'ntially-compressed condition, each 1 ofsaid ends being provided with a return bentportion, each return bentportion forming an acute included angle with the contiguous portion ofsaid parted ring, the bottom of said oil groove having a predeterminedmaximum spacing from said bore when said piston and oil ring assembly isinserted within said bore, and the combined thicknesses of twocontiguous portions and one return bent portion plus the rail widthbeing greater thansaid predetermined maximum spacing whereby if saidspacerexpander ends are overlapped the piston oil ring'assembly has adiameter through the overlap that is greater than the diameter of thebore. i

said spacer-expander is formed from a strip of resilient material andthree thicknesses of said strip plus-the width of said rail are greaterthan said predetermined maximum said parted ring having ends that abutwhen said spacerexpander and said rails are disposed in an oil ringgroove it andsaid spacer-expander is-in its operativecircumferentially-compressed condition, each of said ends being providedwith a return bent portion, each return bent portion forming an acuteincluded angle witha radius. of said parted ring.

15. A spacer-expander for use in a piston oil ring assembly of the typeadapted to be retained in an oil ring groove of a piston when the pistonis disposed in a cylinder bore with a predetermined maximumspacingbetween the oil ring assembly andnthe bottom of the toil ringgroove, said spacer-expander comprising a parted ring of theself-supporting type, said parted ring having ends that abut when saidspacer-expander and said rails are disposed in an oil ring grooveand'said spacer-expander is in its operativecircumferentially-c-ompressed condition, each of said ends beingprovided with a return bent portion forming an acute included anglewith-the contiguous portion of said ring, and the combined thicknessesof a return bent portion and a contiguous ,portion being greaterthansaid predetermined maximum spacing whereby if said ends of saidspacer-expander are inadvertently overlapped, the combined-thicknessesof a return bent portion and a contiguous portion prevents contractionof minedmaximum spacing fromthe bottom of the oil ring groove when saidrails abut the ,wall of ,said bore, and V the combined .IhiCknesses ofa' eturn bentxpori n and a contiguougportion being greater than said,predeterined maximum spacing whereby the combined thicknesses of areturn bent portion and a contiguous portion prevent contractions ofsaidqrailsradiallysufiiciently to permi-tinsertion of the piston withthe oil ring assembled thereon within said cylinder'when the ends .ofsaid-spacer? expander are overlapped.

17. A spacer-expander of the self-supporting type for supporting,spacing, and outwardly urging generally flat,

.1 parted rails in a piston oil ringassembly, said spacer-ex? on theother "end corrugation when saidring is in an operativecircumferentially compressed condition,,said. one end corrugation havinga radial leg remote from said abutting portion, said inner crownsdefiningthe inner periphery of said spacer-expanden the outer crowns deae v 40 12. The combination as set forth in claim 11 wherein said overlapzone projecting into, said overlap zone and pander comprising a partedring formed with radial corrugations comprising an alternating series ofinner and' outer crowns with alternate crowns connected by generallyradial legs, one end corrugation of said spacer-expander having an endportion that abuts an end portion fining the outer periphery of saidspacer-expander, a Zone of potential overlap on said one end corrugationdefined radially between said inner and outer periphery of saidspacer-expander and defined circumferentially between said remote radialleg and said abutting portion, and means for resisting nesting ofsaidend corrugations at spaced radially from the crown of said one'endcorruga- 7 tion and spaced circumferentially from said remote radiallegot said one end corrugation less than the circumferential'dimensionof the crown of said other end corrugasaid one end corrugation is aradially inward corrugation tion whereby it said end corrugations areoverlapped, 50"

- piston oil ring assembly has a diameter through the over lappedcorrugations that is greater than the diameter of nesting of said endcorrugations is resisted so that said an engine cylinder into which thepiston oil ring assembly is to be inserted to thereby indicate that saidendcorru gations are overlapped. i V 18. The spacer-expander set forthin claim 17, wherein havingan inner crown and said projecting meansextends in a direction radially outward from said last mentioned innercrown. I

19. The spacer-expander set forth in claim 17 wherein said projectingmeans terminates within said zone.

20. The spacer-expander set forth in claim 17 wherein i said one endcorrugation has a return bent tab forming an elbow, said abuttingportion comprising the bend of 831d elbow, and said projecting meanscomprising the free end of said return bent tab.

21. In a piston and oil ring assembly adapted for insertion into anengine cylinder, an oil ring groove in said.

piston retaining said oil ring, said oil ring comprising flat,'partedcircular rails and a spacer-expander for'supporting'and spacingsaid rails and for urging said rails outwardly against thewall of saidcylinder, saidspacerexpander. comprising a, parted ring formed withradial corrugations, comprising an alternating series of-inner areai'sar {and outer crowns with alternate browns" Connected by generally'radial legs, one end corrugationof said spacereXpander having a'n-endportion that abuts an end portiorion the other end'corrugation when saidring is in an operative circumferentially compressed condition, said oneend corrugation having a radial leg remote from said abutting portion,saidjnner crowns defining the inner -periphery of said spacer-expander,the outer crowns defining the outer periphery of said spacer-ex--pander, a zone of potential overlap on said one end corrugation definedradially between said inner and outer periphery of said spacer-expanderand defined circumferentially between said remote radial leg and saidabutting portion, an abutment" on said one end corrugation projectinginto said overlap zone so as to be spaced radially from thecrown of saidone end corrugation and spaced circumferentially from said remote radialleg of said one end corrugation less than the-circumferential dimensionof the crown of said other end corrugation,

the radiallyinnerrnost portion of said oil ring having apredeterminedmaximum spacing from the bottom of the oil ring groove whensaid rails abut the wall of said cylinder, the radial dimension of theradial space he ."tween said projection "and said inner periphery ofsaid 1 spacer-expander being greater-i'thansaid predetermined ReferencesCited by theExalniner :UNITED STATES PATENTS 326,046 V 9/85 Love -277147 2,059,179 10/36 Smith s .26;7- -,15 2,112,425 3/38 'Nixon'. 26 7-152,466,252 4/49 McFall 277-148 2,7s9 ,s72 .4/57 ,Olson 1 -2;77 1392,917,353 12/59 .Baumleretal. 2774139.

EDWARD v, BENHAM, Pr'iir try Examiner. SAMUEL ROTHBERG, Examiner.

Patent No. 3,166,531 January 19, 1965 Frank G. Warrick ears in the abovenumbered patertified that error app Patent should read as It is hereby cctio'n and that the said Letters ent requiring corre corrected below.

Column 5, line 38, before "0'11" insert and Signed and sealed this 1stday of June 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Commissioner of Patents

1. A SPACER-EXPANDER FOR SUPPORTING, SPACING AND OUTWARDLY URGINGGENERALLY FLAT, PARTED RAILS IN A PISTON OIL RING COMPRISING A PARTEDRING OF THE SELF-SUPPORTING TYPE, SAID PARTED RING HAVING ENDS THAT ABUTWHEN SAID SPACEREXPANDER AND SAID RAILS ARE DISPOSED IN AN OIL RINGGROOVE AND SAID SPACER-EXPANDER IS IN ITS OPERATIVECIRCUMFERENTIALLY-COMPRESSED CONDITION, EACH OF SAID ENDS BEING PROVIDEDWITH A RETURN BENT PORTION, EACH RETURN BENT PORTION FORMING AN ACUTEINCLUDED ANGLE WITH THE CONTIGUOUS PORTION OF SAID PARTED RING.